1. Field of the Invention
The present invention generally relates to a communication system transmitting information for communication between user terminals connected to each other by way of communication networks such as the Internet, and, more particularly, to a communication system transmitting communication information between user terminals which access network resources by way of communication networks.
Further, the present invention is concerned with a network system including the communication system.
2. Description of the Related Art
A chat system, for example, NetMeeting.TM. of Microsoft Corp., is known as a communication system which uses communication networks such as the Internet. In this case, if a user accesses a server used only for the chat system, a list of names of the users is shown to the user, and the user can chat with the other users.
In the case of Onlive.TM. provided by OnliveTechnology Inc., it is known that a virtual image of a user accessing a virtual space is shown in the virtual space and the user can chat with virtual images of the other users which the user meets in the virtual space.
Further, U.S. Pat. No. 5,764,916 of ichat Inc. discloses a chat system using a server only for chat. In the system, a client sends a chat message which contains HTML (Hyper Text Markup Language) including a URL (Uniform Resource Locator) to another client. Then, the client who receives the message can chat while they are watching the same HP (Home Page) of the URL.
Proxy servers are known as devices which manage both IP addresses of user terminals necessary for chat and URLs which the user terminals access.
However, in the system such as Netmeeting.TM. used only for chat and separated from an HP, a user cannot know which HP the other users are accessing while the user is chatting with the other users. Therefore, it is not easy for a plurality of users to chat while they are accessing the same HP.
In a chat system such as the Onlive.TM. system which is contained in the WEB, users can chat while they are accessing an Onlive.TM. HP. However, on other home pages which do not include any chat system, users cannot chat while sharing the same home pages.
Further, the method which is disclosed in the U.S. Pat. No. 5,764,916 of ichat Inc. has the following disadvantages. A user must write URLs in chat messages and send the messages, and it is not obvious to the user that the receiving user is really accessing the home page of the URL. Also if a user moves to another home page, the other users cannot know about the move unless the user lets them know about the move in some way. Therefore, users cannot chat while sharing home pages dynamically by the method.